Naphthol Research Articles

Ready-to-use diagnostic kit based on electrochemical nanobiosensor for antibiotic resistance gene determination

Nowadays, antibiotic resistance, which occurs as a result of mutations in bacterial genes due to the frequent use of antibiotics, causes serious health problems and deaths. One of the resistance mechanisms that develop with the use of antibiotics is that bacteria begin to produce carbapenemase enzymes that cause multiple drug resistance in bacteria by hydrolyzing antibiotics. In this study, an alternative diagnostic kit method to traditional tests was developed for the determination of bacteria carrying relevant antibiotic resistance genes because these analyzes have multi-step sample preparation, long/complex determination schemes and are high cost.With the diagnostic kit containing a stable electrochemical nanobiosensor developed in this study, the presence of two different antibiotic resistance gene regions of the carbapenemase enzyme named OXA-48 and VIM, which are responsible for more than 50 % of deaths due to antibiotic resistance, was investigated. Carbon nanotubes (CNTs) has been modified to the pencil graphite electrode (PGE), then the synthetic capture probe DNAs are immobilized covalently to the surface containing nanomaterial. Later, the sensor surface, whose stability was ensured by surface blockage, thus gained “diagnostic kit feature” and was stored in the refrigerator (+4 °C) until analysis. Thus, the preparation of a ready-to-analyze diagnostic kit, which will provide detection without any preparation, has been completed. With the developed kit, it was possible to determine the resistance gene with 2.5 pmole/50 μL of detection limit. In addition, analyzes with real samples could be performed even after 150 days (5 months) of kit preparation.This represents the first diagnostic kit system containing PGE and CNT for the detection of antibiotic resistance based on electrochemical alpha naphthol signal measurement in real samples with symmetrical and asymmetric structures (PCR). In the developed alternative test platform, the sample volume required for determination is 50 μL and the analysis time with this portable open-use and throw-away diagnostic kit is 30 min.

Development of Ti4O7 reactive electrochemical membrane and electrochemical oxidation of naphthols in aqueous solution

Naphthols (NAPs), commonly used phenolic compounds, have significant impact on environmental risk and human health, necessitating advanced treatment methods for their degradation. In this study, a Ti4O7 reactive electrochemical membrane (REM) was developed for the electrochemical oxidation of NAPs. The Ti4O7 REM presented a porosity of 42.18 ± 2.3% and a median pore diameter of 1.21 µm. High permeability (846 LMH bar−1) was achieved at relatively low transmembrane pressure and resulted in a convection-enhanced rate constant for Fe (CN)64- oxidation of 1.7 × 10−4 m/s. The increase in current density and decrease in plate spacing had a positive influence on NAPs degradation. The TOC removal efficiencies of 1-naphthol (1-NAP) and 2-naphthol (2-NAP) were 68.6% and 63.5%, respectively at the current density of 6 mA/cm2 and plate spacing of 10 mm. Additionally, quantum chemical calculation using density functional theory (DFT) was employed to identify the active sites of NAPs through atom charge and frontier electron density (FED) calculations. Results showed that C14 and C10 were identified as the active sites for 1-NAP, while C9 and C13 were the active sites for 2-NAP. Hydroxyl radical and sulfate radical produced on the electrode surface were the main oxidants for NAPs degradation during the electro-oxidation process. The degradation pathway included hydroxylation, oxygenation, decarbonylation, and ring-open processes, which was in agreement with the theoretical calculations. Furthermore, the quantitative structure-activity relationship (QSAR) predictive model was used to assess the toxicity changes during the electrochemical oxidation process of NAPs, suggesting that the toxicity of intermediates increased at the beginning and significantly reduced at the end. This comprehensive study provides practical and theoretical insights into the application of electrochemical oxidation technique for the reduction of refractory compounds in wastewater.

DEVELOPMENT AND QUANTIFICATION OF HORSERADISH PEROXIDASE USING PARAPHENYLENEDIAMINE AND ALPHA NAPHTHOL: APPLICATIONS IN MEDICINAL PLANT SOURCES

In this work, a unique calorimetric system was presented for the determination of horseradish peroxidase (HRP) and hydrogen peroxide (H2O2). This HRP-catalyzed system is based on the formation of electrophilic 1,4 –diimine by the oxidation of Paraphenylenediamine (PPD), this intermediate undergoes coupling with the free para position of Alpha naphthol (AN) to generate the stable intense purple-colored radical with λmax 520nm had good linear with peroxidase concentration 0.08-1.32 nm and 0.02-0.66 nm by kinetic and one-time detection method and H2O2 amid 0.6 – 38.7 µM from the kinetic and 0.07- 4.83 µM by fixed time method, respectively. Moreover, the applicability of the proposed PPD-AN system has been successfully used to detect HRP activity in medicinal plants with crude extract as the source of enzyme and the outcomes were compared with the reference method. Overall, the present system can be adopted as a candidate system for the determination of H2O2.

Promising approach to the synthesis of unknown 2-(2, 2′-diamino-4,5′-dipyrimidin-6-yl)phenols(naphthols) and 2-amino-6-(2-hydroxyphenyl)-4-(4-nitrophenyl)nicotinonitriles

Promising approach to the synthesis of unknown 2-(2, 2′-diamino-4,5′-dipyrimidin-6-yl)phenols(naphthols) and 2-amino-6-(2-hydroxyphenyl)-4-(4-nitrophenyl)nicotinonitriles

Copper-Catalyzed ortho-Functionalization of Naphthols and Phenols

Key words copper catalysis - C–H functionalization - ortho-functionalization

Electrochemical sensing platform for naphthol isomers based on in situ growth of ZIF-8 on reduced graphene oxide by a reaction-diffusion technique

Enhancing the dispersibility and conductivity is an effective solution to develop the application zeolitic imidazole frameworks (ZIF) in the electrochemical field. This work thus employs a novel reaction–diffusion framework (RDF) technique for the in situ growth of ZIF-8 crystals on graphene oxide (GO@ZIF-8) matrixes. In detail, the outer electrolyte of 2-methyl imidazole naturally diffuses into the inner agar gel matrix containing Zn2+ cations and GO nanosheets. The long reaction–diffusion makes the growth of ZIF-8 crystals controllable in a vertical gradient. After thermal treatment, the title product of ZIF-8 in situ grown on reduced graphene oxide (rGO@ZIF-8) is obtained and thus exhibits good dispersibility, high conductivity, large surface area, and more catalytic sites. The glassy carbon electrode (GCE) was modified by casting the rGO@ZIF-8 suspension. The obtained rGO@ZIF-8/GCE displays excellent catalytic activity toward naphthol (NAP) isomers. Under the optimal conditions, the amperometric currents of 1-NAP and 2-NAP demonstrate the good linear relationship in wide ranges of 0.05–12 μM and 0.02–15 μM, respectively. Their limits of detection are as low as 15 and 17 nM, respectively. The fabricated modified electrode exhibits excellent selectivity, stability, and reproducibility. The sensor is also utilized to detect NAP molecules in real water samples and indicates good accuracy and reliability.

Effect of an Alkoxyliertes Beta Naphthol on Cu Electrodeposition for Application to Low‐Resistivity Cu Interconnects

Cu thin films were electrodeposited using electrolytes containing alkoxyliertes beta naphthol (ABN) as an organic additive, which shows a strong suppressing effect similar to PEG10000. The surface roughness of Cu thin film decreased, while the grain size remained unchanged with increasing ABN concentration. Consequently, the resistivity of Cu thin film was reduced by 41% compared to Cu thin film electrodeposited using pure electrolyte. In addition, the void free interconnect wire was fabricated by filling of 70‐nm wide trench using only ABN, without the help of any accelerator or leveler.

Synthesis, Characterization and Antimicrobial Analysis of 1-(1-Phenylazo)-2-Naphthol

Synthesis, Characterization and Antimicrobial Analysis of 1-(1-Phenylazo)-2-Naphthol

Introduction of in-plane π-conjugated heterojunction via rGO modulation: A promising approach to enhance photoexcited charge separation and transfer of g-C3N4

Abstract Efficient separation of photoexcited charge is the bottleneck of photocatalysis in the practical application. Design and construction of the heterojunction with proper interface and rational electronic structure is urgently needed to overcome this limitation. Here, we propose a conceptual design of in-plane heterostructure with continuous π-conjugated bond through the incorporation of reduced graphene (rGO) into graphitic carbon nitride (g-C3N4). The unique in-plane heterostructural rGO/g-C3N4 nanosheet realizes high photogenerated electron-hole pair separation efficiency through the π-conjugated build-in electric field at the interface. Incorporation of rGO endows the photocatalyst a wider photoresponse window and better oxidizability, beneficial for light absorption and redox reaction. Consequently, the in-plane rGO/g-C3N4 heterostructure can enhance photocatalytic water purification performance towards different kinds of pollutants (such tetracycline, beta naphthol, rhodamine B, etc.). Notably, the photocatalytic rate of 5 wt%rGO/g-C3N4 are estimated to be 3.89 (tetracycline), 5.17 (beta naphthol), and 6.00 times (rhodamine B) higher than g-C3N4, respectively. This new insight of interface incorporation engineering helps to inspire innovative semiconductor structural designs with fast charge transfer and satisfied photocatalytic activity.

Rhodium(III)-Catalyzed C–H Activation Towards Polyarylated Naphthols

Rhodium(III)-Catalyzed C–H Activation Towards Polyarylated Naphthols

Diagnosis and treatment of adult acute myeloid leukemia with NPM-MLF1 fusion gene and literatures review

Objective To evaluate the clinical features, treatment and prognosis of acute myeloid leukemia (AML) with nucleophosmin (NPM)-myelodysplasia/myeloid leukemia factor (MLF)1 fusion gene. Methods On 16 February 2016, a case of AML patient with NPM-MLF1 fusion gene who was admitted to Changhai Hospital Affiliated to Second Military Medical University was included in this study. When the patient was admitted, bone marrow morphology, cytochemical staining and immunophenotype analysis of leukemia blasts, cytogenetics and molecular genetic analysis were conducted and diagnosis was made base on those test results. On 17 February 2016, the patient recieved two courses of daunorubicin+ arabinosylcytosin (DA) 3+ 7 induction therapy. Subsequently, the patient recieved one course of fludarabine, cytarabine and granulocyte colony-stimulating factor (FLAG) regimen and 5 courses of high-dose of cytarabine. In the meantime, bone marrow morphology and minimal residual disease (MRD) were conducted during the chemotherapy. On 6 April 2017, the patient received bone marrow morphology, immunophenotype analysis of leukemia blasts and molecular genetic analysis on her visit. The clinical features, diagnosis and treatment of this patient were analyzed retrospectively, and the related literatures were reviewed. Results ①When the patient was admitted, bone marrow morphology revealed hyper-cellular marrow with 48.0% leukemia blasts. Cytochemical staining showed that peroxidase (POX) staining in some leukemia blasts were positive, and naphthol AS-D chloroacetate esterase (CE) staining in a few leukemia blasts were positive, and non-specific estertase (NSE) staining in some leukemia blasts were positive. The results of immunophenotype analysis revealed the ratio of the blasts cell was about 39.9%, and the ratio of immature cell was about 13.6%. R banding karyotype analysis marked with 46, XX, t(3; 5)(q25; q34)[3]/46, XX[7]. Molecular genetic analysis showed NPM/MLF1 fusion gene was positive. According to above, the diagnosis of patient was AML-subtype M4 with NPM-MLF1 fusion gene. ②After the patient was treated with the first course of induction therapy, and the reexamined bone marrow morphology post therapy showed partial remission (PR). The patient received complete remission (CR) after the second course of induction therapy. After the patient received consolidation therapy, and bone marrow morphology showed the patient obtained sustained CR status. On the patient′s last visit, bone marrow morphology revealed a total of 25.0% leukemia blasts, consisting of 21.0% blasts and 4.0% immature cell, suggesting AML recurrenced. Immunophenotyping of leukemia blasts showed approximately 28.5% of the early myeloid cells in bone marrow which was consistent with AML recurrence. Molecular genetic analysis showed that the MPM-MLF1 fusion gene was positive (66.1%). During the treatment, bone marrow MRD decreased, then increased. The patient went back to local hospital for treatment after AML relapsed. Conclusions AML-subtype M4 patient with NPM-MLF1 fusion gene can achieve CR after chemotherapy, but prone to early recurrence, and NPM-MLF1 fusion gene may be a poor prognostic factor for AML. Key words: Leukemia, myeloid, acute; Drug therapy; NPM-MLF1; t (3;5)

Novel Z-Scheme g-C 3 N 4 /C@Bi 2 MoO 6 composite with enhanced visible-light photocatalytic activity for β-naphthol degradation

Abstract A novel ternary g-C 3 N 4 /C@Bi 2 MoO 6 composite photocatalyst was prepared by a hydrothermal deposition method. Beta naphthol (β-naphthol) was effectively degraded over g-C 3 N 4 /C@Bi 2 MoO 6 composite under visible-light irradiation. The improved photocatalytic activity could be attributed to the efficient separation of photogenerated electrons and holes through the Z-scheme construction of g-C 3 N 4 /C@Bi 2 MoO 6 . Carbon film acted as an electron mediator to form the charge transmission-bridge between Bi 2 MoO 6 and g-C 3 N 4 , which provided sufficient contact area and strong combination between the semiconductors and the electron mediators. The optimized Z-scheme 10%g-C 3 N 4 /C@Bi 2 MoO 6 composite showed the highest photocatalytic activity. A possible photocatalytic mechanism of g-C 3 N 4 /C@Bi 2 MoO 6 was proposed by a trapping experiment, which could be ascribed to the oxidizing ability of the generated holes and light absorption as well as the reduced the electron–hole pairs recombination with the presence of g-C 3 N 4 and carbon in the composites. The photogenerated holes in the valence band of Bi 2 MoO 6 were the major species in the β-naphthol photocatalytic degradation process, and the accumulating electrons in the conduction band of g-C 3 N 4 could capture the molecular oxygen to form superoxide radicals to decompose β-naphthol.

Electrochemical Determination of Cystic Fibrosis Gene Mutation by Magnetic Beads-Based Disposable Kit-type Biosensor

This paper introduces a disposable magnetic beads-based DNA biosensor for the rapid, sensitive and selective detection of Delta F508 (ΔF508del) Cystic Fibrosis (CF) gene mutation for the first time. The developed protocol contains the use of streptavidin-coated magnetic beads (MBs) and disposable screen printed carbon electrodes (SPEs). In the study, biotin-tagged specific capture probe was firstly immobilized on streptavidin-coated MBs and the modified beads were stored at 4°C in the form of a “kit” until the analysis of target DNA. The probe contained easy-constructed MBs kit was then incubated with the target DNA for hybridization. The detection of hybridization was identified based on enzymatic (alpha naphthol signal-based) or label-free (guanine signal-based) methods by using differential pulse voltammetry (DPV). The genosensor response was stable up to 6 months of storage period of the kit and the detection limit (LOD) of 0.5 picomole in 45 μL of sample volume was obtained for a 18-mer synthetic target with in 30 min detection time.

Neuropathic organophosphates: from Scrugham, Heim and Lorot to Jake leg paralysis.

Henry Scrugham (1811-1898), the father of triphenyl-phosphate, was a student of Alexander Williamson (1824-1904), Professor of analytical and practical chemistry at the University College London. Williamson using the approach perfected by Scurgham reacted phosphorus pentachloride with cresol (a mixture of ortho, para and meta isomers) thus obtaining tricresyl phosphate (TCP). The triesters of phenol, cresol and naphtol were prepared with a higher yield by Rudolf Heim (1861-1919) by their respective reaction with phosphorus oxychloride (POCl3). Heim is also the first one to obtain pure tri-o-cresyl phosphate (TOCP). In the meantime French pharmacist Jules Brissonnet (1859-1915) synthesized creosote phosphate (containing i.a. TOCP) and popularized its use in the treatment of pulmonary phthisis (tuberculosis). Camille Lorot (1872-1951) and others in France and Germany recognized the ability of creosote phosphate to induce polyneuropathies but this knowledge did not prevent the Ginger Jake epidemic (Jake leg) of the 1930s in the US. The Jake induced neuropathy was first recognized and described in Oklahoma City by a General Practitioner, Ephraim Goldfain (1894-1983). Soon thereafter Maurice Isadore Smith (1887-1951), a pharmacologist, and chemist Elias Elvove (1883-1962) identified TOCP in Jamaican ginger extract as the causative agent. We attempt to shed some light on the life and family of the less known chemists, pharmacists and physicians associated with the synthesis of neuropathic organophosphates and with the recognition of their toxicity.

Capillary electrophoresis chemiluminescence assay of naphthol isomers in human urine and river water using Ni(IV) complex-luminol system.

A capillary electrophoresis method involving online indirect chemiluminescence (CL) detection was used to determine naphthol (NAP) isomers. The method was based on the quenching effect of 1- and 2-NAP on a new CL reaction of luminol with Ni(IV) complex in an alkaline medium. Separation was conducted with a 25.0 mM sodium borate buffer containing 0.8 mmol/L luminol. Under optimized conditions, 1- and 2-NAP were baseline separated and detected in less than 8 min. The limits of detection of 1- and 2-NAP were 3.1 and 2.7 μg/L, respectively (S/N = 3), with a linear range of 4.0-80.0 μg/L (r > 0.995). Analysis of real samples demonstrated that the spiked recoveries were in the range of 89.2-107.5% (n = 3). The proposed method was successfully used to determine 1- and 2-NAP contents in three environmental water samples and 14 human urine samples. No derivatization or tedious pretreatment was required in the analysis. The proposed method is a potential approach for routine tests of naphthol isomers in a facile CE-CL system.

Adsorption of Mixture of Two Dyes on Activated Carbon

Activated carbon is known as adsorbent to various contaminants from wastewater and air. The aim of work was to estimate sorptive capacity of activated carbon in the removal of dyes, which are contaminants from textile wastewaters. The mixture of two dyes, methyl blue and naphtol green B were chosen to study, and as adsorbent we have chosen the activated carbon WDex, virgin and regenerated. Dye concentration in both cases was 200 mg/dm. Sorption abilities of activated carbon were expressed by mass balance relationship in case of fresh activated carbon it was 60 mg/g, and after regeneration from 8 to 13 mg/g. The experimental data adsorption isotherms were defined and adsorption theoretical model such as Freundlich or Langmuir, was selected. The highest removal efficiency in case of methyl blue was 94% for virgin carbon, the lowest 75% (carbon after 4 regeneration). The highest removal efficiency in case of naphtol green B was 78% for carbon after IV regeneration, the lowest 55% (carbon after 1 regeneration). The experimental data shows that activated carbon can be used for the decontamination of dyes from textile wastewater. However, model tests need to be verified on real wastewater samples.

Spectrophotometric Determination of Copper(II) in Sugarcane Spirit Using 1-(2-pyridylazo)-2-naphthol and a Homogeneous Ternary Mixture of the Solvents Water, Ethanol and Methyl Isobutyl Ketone

Uma nova tecnica analitica rapida, barata e sensivel e descrita para a determinacao espectrofotometrica de ions cobre(II) em aguardente de cana-de-acucar, empregando o agente complexante 1-(2-piridilazo)-2-naftol (PAN). Sistemas ternarios homogeneos de solventes, comumente denominados de solucao fase unica, podem ser utilizados como alternativa para pre-concentracao de amostras. Por tal razao, empregou-se uma mistura dos solventes agua-etanol-metilisobutilcetona (MIC), na proporcao 5,0:5,0:2,5 v/v respectivamente. A maxima formacao do complexo bis[1-(2-piridilazo)-2-naftalato]cobre(II) ( Cu(PAN) 2 ) ocorreu com 0,01% m/v de PAN em MIC, pH de 4,50 da fracao aquosa, 15 minutos de tempo de reacao e 20 °C de temperatura. Foi verificado que os ions ferro(III) e niquel(II) interferiram na reacao. Acido malonico a uma concentracao de 0,10% m/v foi, portanto utilizado como agente mascarante, na qual reduziu a magnitude dos efeitos de interfrencia de 10,4% para aproximadamente 2,6%. Nas condicoes otimizadas de determinacao de cobre(II), a curva analitica obtida pode ser descrita por: ?Abs = 0,152 C Cu(II) + 0,011 (r 2 = 0,9997). A linearidade foi obtida ate uma concentracao de 8,00 mg L -1 de cobre(II), e limite de deteccao e de quantificacao (calculados usando o desvio padrao do branco) foram 0,02 mg L -1 e 0,13 mg L -1 de cobre(II), respectivamente, na fracao aquosa da solucao fase unica. O metodo foi aplicado para determinar ions cobre(II) em amostras comerciais de aguardente de cana-de-acucar. Os resultados obtidos pelo metodo proposto foram estatisticamente iguais com os obtidos pelo metodo padrao. DOI: 10.5935/1984-6835.20160052

Colorimetric detection of coxsackievirus A6 by reverse transcription loop mediated isothermal amplification

To develop a simple, rapid and sensitive colorimetric reverse-transcription loop-mediated isothermal amplification (RT-LAMP) for rapid detection of coxsackievirus A6 (CV-A6) based on the colour chang of hydroxy naphthol blue (HNB). The method employed a set of six primers that recognized sequences of VP1 gene for amplification of nucleic acid under isothermal conditions at 63 °C for 50 min. The products were detected through visual inspection of color change by the pre-addition of HNB dye. The specificity was validated by detecting a collection of different human enteroviruses. The sensitivity of this assay was evaluated by serial dilutions of RNA molecules from in vitro transcription of CV-A6 VP1 gene, and compared with real-time RT-PCR (rRT-PCR) in parallel. This assay was evaluated with 92 clinical specimens from patients with hand-foot-mouth disease. A positive color (sky blue) was only observed in the preparation of CV-A6, whereas none of the other 23 kinds of human enteroviruses showed a color change. The HNB based RT-LAMP showed a sensitivity of 100 copies/reaction, which was at the same level as that of the rRT-PCR. The result of RT-LAMP in analysis of 92 clinical specimens was consistent with that of the rRT-PCR. The kappa correlation between the two methods was 1 and both of the sensitivity and specificity of the RT-LAMP assay were 100%. The established RT-LAMP assay had good specificity and sensitivity and thus demonstrated to be a promising screening tool for CV-A6 infection. It also has the potential to be used in resource-limited clinical sites and field study.

Synthesis of 5-Fluorinated Naphthols

Synthesis of 5-Fluorinated Naphthols

Novel removal of Anthracene from oil-contaminated water by synthesized modified magnetic nano-particles

Novel magnetic nanoparticles (MNPs) modified with (3-mercaptopropyl)-trimethoxysilane (MPTMS), grafted with allyl glycidyl ether and coupled with beta naphthol, were prepared for removal of anthracene in aqueous solutions. The grafted MNPs were characterized by transmission electron microscopy (TEM), infrared spectroscopy (FT-IR) and thermogravimetric analysis (TGA). The modified MNPs contributed to enhancement of the adsorption capacity and were prepared by co-precipitation. The modified MNPs were characterized by TEM, FT-IR and TGA and the adsorption and kinetic behavior of anthracene on the modified MNPs was examined. It was shown that the nano-adsorbent optimized adsorption capacity is at pH 7. Three kinetics models: pseudo-first-order, pseudo-second-order, and intraparticle diffusion were used to investigate the adsorption mechanism of the anthracene onto the modified MNPs. The best fit was obtained for the pseudo-second-order model. The synthesized nano adsorbent can be considered as a new method for anthracene adsorption in contaminated water with the benefit of fast removal by applying a magnetic field.